Ratios and Proportions
Proving Proportions
To Prove the
Proportion Solution is
Correct,
Substitue the
Unknown X with the
Found Number.
Proving
the Answer
3
:
4
::
X
:
8
4
X
=
3 * 8
4
X
=
24
X
=
24
÷
4
X
=
6
3
:
4
::
6
:
8
Means
4 * 6
=
3
:
4
::
6
:
8
Extremes
4 * 6
=
3 * 8
24
=
24
If the Product
of the Means
Equals the
Product of the
Extremes,
then the Proportion
is Equal and your
Answer is
Correct.
More Examples of
Proving Equal Proportions
3
:
10
::
6
:
X
10 * 6
=
3X
60
=
3X
60 ÷ 3
=
X
20
=
X
3
:
10
::
6
:
X
3
:
10
::
6
:
20
10 * 6
=
3 * 20
60
=
60
* * * * * * *
5
:
15
::
X
:
3
15X
=
5 * 3
15X
=
15
X
=
15 ÷ 15
X
=
1
5
:
15
::
X
:
3
5
:
15
::
1
:
3
15 * 1
=
5 * 3
15
=
15
* * * * * * *
2
:
7
::
8
:
X
7 * 8
=
2X
56
=
2X
56 ÷ 2
=
X
28
=
X
2
:
7
::
8
:
X
2
:
7
::
8
:
28
7 * 8
=
2* 28
56
=
56
* * * * * * *